Wakeless torpedo



Sept. 11, 1934. E A SPERRY l 1,973,545

I WAKELEss 'TORPEDO Original Filed July 6, 1923 3 Sheets-Sheet 1 2 5 wgl. 10 54 53 48 IIIIIIIIAIIInIIII- ln- Sept. 1l, 1934. Y E, A. SPERRY A 1,973,545

WAKELES S TORPEDO Original Filed July 6, 1923 3 Sheets-Sheet 2 s0 7j 35 72 y 4 llllllllllllll y?? INVENTOR ELMEE /LSPEBBY Sept. 11, 1934. E A SPERY 1,973,545

WAKELESS TORPEDO I original Filed July 6. 1923 s sheets-sheet 5 INVENTOR ELMEE HSPE'IZBY ED Me GMSPEBEK :xfa/rag l! W ATTORNE Patented Sept. il, 1934 unirsi) STATE-s PATENT OFFICE WAKELESS TORPEDO original application July s, 1923, serial No. 649,881;- Divided and this application September 15, 1931, serial No. 562,864v

8 Claims. (Cl. 114-24) This invention relates to torpedoes and has for its principal object the provision of a torpedo whose trajectory through the water is unaccompanied by a visible wake which heretofore has frequently enabled a ship to avoid torpedoes. This application is a division Aof copending application Serial No. 649,881, filed July 6, 1923. The visibility of the trajectory of a torpedo Aheretofore employed has been due entirelyto the release from the torpedo of a large quantity of air from the compressed air driving plant of the torpedo. The released air rising to the surface formed a track' of white foam six to ten feet wide which was easily visible at a great distance. This invention therefore provides a driving plant for the torpedo which yields no Wake or other visible indication of its path, thereby lgreatly enchancing its value as a weapon of naval warfare.

A further object of this invention is the provision of a driving plant as described which will increase the effective range of the torpedo without increasing the weight, bulk or expense of the power plant.

To provide a power plant as described, I employ steam as the active agent so that when it has expended its force and is discharged into the water, it is condensed without any visible effect. For producing steam there may be employed as oxyhydrogen flame acting upon a supply of water. It is a further object of my invention to provide sources of compressed oxygen and hydrogenand suitable means for igniting the same.

A further object is the provision of a firequenching partition between the sources of compressed gases.

A further object of the invention is the provision of means for supplying oxygen and hydrogen to the combustion chamber in such manner in starting the device to avoid possibility of explosion.

A further objectis the provision of means connected to the combustion chamber whereby the maximum pressure Within said chamber may be controlled at will.

A further object is the provision of differential means whereby the pressure within the combustion chamber controls the rate of oW of water from a storage-tank to said chamber wherein it is converted by the heat of the Oxy-hydrogen iiame into steam.

A further object is theprovision of means for detecting the presence of an excess of hydrogen and for automatically controlling the ow of oxygen and hydrogen to decrease one and increase the other depending upon whether there is an excess or a deficiency of hydrogen.

A further object is the provision of means within the torpedo for operating the depth control means thereof to maintain the torpedo at a pre-determined distance below the surface of the water and for performing said operation without rendering the path of the torpedo visible.

A further object is the provision of means within the torpedo for operating the steering rudder to maintain the torpedo upon a predeter-v mined course and for performing said operation withoutr'endering the path of the torpedo' visible.

A further object is theprovision of a continuously burning cartridge within the combustion chamber.

A further object of this invention is the utilization of the power plant hereinbefore set forth for spinning up the director gyro within the torpedo.

Other objects and advantages will become apparent as the description of the invention proceeds.

In the accompanying drawings,

Fig. 1 is a longitudinal section through a portion of a torpedo constructed according to my invention.

Fig. 2 is a section through the tail of the torpedo showing a part of my invention embodied therein.

Fig. 3 is a detail of the depth-control mechamsm'.

Fig. 4 is a view similar to Fig. 1 but employing a. modified form of the structure shown in the latter figure.

Fig. 5 is a side elevation of a torpedo having a portion thereof broken away to disclose another modification.

Fig. 6 is a section through a device for spinning up the director gyro.

Fig. 7 is a diagrammatic representation of various controlling devices, an showing also a hydrogen detector.

Fig. 8 is a section through the torpedo casing showing a condenser for disposing of the exhaust steam.

Within the torpedo shell 1, there is positioned a plurality of asks 2 and 3 containing diiferent before hydrogen and gases under higlripressure (from 2000 to 3000 lbs. per sq. in.). The? gases are so selected that they will unite' chemically with the production of a maximum amount of heat and also so that the resulting product of combustion is ayapor or a gas, which will condense in its entirety to a liquid or solid before or upon being discharged from the torpedo into the water. The gases preferred in this invention are hydrogen and oxygen, although other combinations of elements l'which will satisfy the above requirements may be used -if desired.

The larger tank 2 is designed for the compressed hydrogen, while the smaller tank `3 is for the compressed oxygen. A gas-trap 4 may be provided between the tanks in the form of a hollow partition filled with a fluid such as water. Said trap will prevent formation of a mixture of gases in either tank with consequent danger of the fiame feeding back from the burner (to be hereinafter described) into the tank and exploding the mixture. The hydrogen is led from tank 2 through pipe 5 to the usual control. and reducing valve 6 which is operated by a trip 'I as the torpedo leaves the launching tube. Preferably the reduction is effected in two stages, first by. a valve 8 shown within tank 2, and second by the valve 6. It will be readily understood by those skilled in the art that the tank pressure of from 2000 to 3000 lbs. is reduced to a uniform pressure of say from 400 to 500 lbs. per sq. in. bysaid valves. Likewise the oxygen is also led through l control and reducing valves 9 and 10, by pipe 14,

the latter of which is preferably operated from the same tripl'l which operates valve 6. The trip 7 is pivoted at 11 and has pivoted thereto above pivot 11 a link 12, so that when trip 'I is actuated by the discharge of the torpedo from the tube,

, link 12 will be moved laterally. During its lateral movement, link 12 opens both valves. The link is connected directly to valve 10 Without lost motion, so that oxygen is supplied to a combustion chamber 15 through pipe 16 as soon as the link 'isi operated. The unk 12 is connected to valve 6, however, by a pin-and-slot connection 18, 19; so that a certain amount of lost-motion occurs before valve 6 is opened to permit hydrogen to flow through pipe 17 to chamber 15. In other words, as trip 'l is actuated by the launching of the torpedo, the oxygen valve is opened a y predetermined period before the hydrogen valve so thai;` oxygen enters the combustion chamber thus permits a flame to be established at the jet immediately that the hydrogen enters, and offers protection against explosion which might result if hydrogen entered chamber 15 mixed with the air present to form an explosive mixture and wasl ignited. The length of time one valve is opened before the other is very slight and is almost simultaneous with said other valve. scribed presupposes that at the beginning of the operation there is no air or other combustionsupporting gas in chamber 15.

From the valves the gases are led to a common burner 20 within the combustion chamber, 15 through the pipes 16 and 17. The exact form of burner employed, or whether or not the oxygen and hydrogen are mixed prior to combustion, is of course immaterial so far as the broad aspects of this invention are concerned. In the form shown, the hydrogen and oxygen are united at the nozzle as in the oxy-hydrogen blow-pipe. The burner 20 is shown as provided with a plurality of nozzles 21 directed in a plurality of The mechanism hereinbefore de-4 directions. It will also be understood by those skilled in the art that the whole chamber is maintained under suitable pressure, say only slightly lower than that of the entering gases, but contrary to existing practice, I employ no alcohol or liquid fuel flame in Vthe chamber, depending entirely upon the burning of the' gases for the production of heat. On account of the much higher temperatures produced by the burning of hydrogen in oxygen than by the burning of alcohol in air, I prefer to provide cooling means for the combustion chamberfpreferably in the form of awater-jacket 22 which may partially or wholly surround the chamber. Il prefer also to spray water into the combustion chamber both to keep the temperature down and to supply a greater volume of superhea'ted steam at workable pressures. The water for the spray is preferably taken from the water jacket and is sprayed into the chamber 15 through a nozzle or nozzles 23. Said nozzles supply the Water preferably from the upper,l hotter portion of the jacket so` that heated water is supplied to the combustion4 chamber. The supply of water for the jacket is maintained by a reservoir 25 through pipe 26 and control valve 27. Preferably said valve is opened by trip 7, as by means of link 28 and valve lever 29.

The water supply is preferably maintained under pressure greater than that of chamber 15, but preferably less than that of tank 2, as by having a connection through branch pipe 30, with pipe 5 between valves 8 and 6, so that water will be atomized as it enters the combustion chamber where it instantly flashes into steam.

For igniting the combustible mixture there may be employed a spark plug 3l in circuit with a spark coil 32 and a suitable source ofY current, such as batteries 33 (see Fig. 7), or I may employ a continuously-burning cartridge or fuse 35, as shown in the modified form of my device in Fig. 4, and adapted to burn continuously for a predetermined time to establish the flame which is thereafter self-sustaining by the ignition of the oxygen and hydrogen mixture. It will be understood that the spark coil 32 or cartridge 35 may ybe employed interchangeably on the Fig. 1 and Fig. 4 devices.

The superheated steam is led by pipe 40 to the turbine 41, while the exhaust steam is taken out through the hollow propeller or tail shaft 42 and is discharged at the tail of the torpedo beyond the propellers 43 and 44 or in any manner best suited to its complete condensation.l A suitable system for condensing, such as a condenser 198 and vacuum pump 199, may be employed in connection therewith, if desired (see Fig. 8). As shown by `the arrows, sea water is circulated around the coils of the condenser by convection. It will be readily apparent, however, that even if the steam Yis discharged directlyl into the water, it will not produce bubbles and foam at the surface such as is produced by the discharge of air in ordinary torpedoes,v since the steam on coming in-contact with the cold water will condense before any of it reaches the surface. It is well known in the art that torpedoes usually travel a 'considerable distance under the surface of the rent to the electrically-driven gyroscope 49 enclosed in casing 50 which is pivotally mounted on a horizontal axis in ring 51 and said ring in turn .60 on an end of the gyro rotor axis 61.

pivotally mounted on a vertical axis in a ilxed bracket 52. The gyro controls the course of the In order to render the generator effective, there may be provided a knife-switch 53 in the vform of a bell-crank having one arm 54 extending outside the casing to be operated during launching of the tube. Since it is desired to have the gyro running at full speed before the torpedo strikes the water, means are provided for spinning up the gyro before the generator becomes eiective. For this purpose the oxygen from tank 3 may be utilized by means of a pipe 55 tapping pipe 14 between valves 9 and 10 to obtain an intermediate pressure. By connecting pipe.55 in advance of or beyond either of said valves, various pressures may be obtained. The oxygen is delivered by pipe 55 to a nozzle 56 adjacent a turbine or bucket wheel 57 mounted upon a shaft 58 having a sleeve 70 thereon upon which is fixed a gear 59 adapted to mesh with a gear Sleeve 70 has engagement with shaft 58 bymeans per-'- mitting rotary movement of shaft 58 independent of sleeve 70 but causing said sleeve and shaft to move together axially. Sleeve 70 is slidably axially in bracket 62 by.` means of a slidable shaft 63 having hubs 64 and 65 thereon engageable on opposite sides of a depending arm 66 fixed to said sleeve, so that gear 59 and turbine wheel 57 -may be moved into and out of engagement with gear 60 and nozzle 56, respectively. Shaft 63 is provided with a locking member 68 adapted to engage in a, socket 69'in the end of the rotor shaft to lock the gyroscope during the initial spinning up. It will be apparent that the oxygen supply will be rendered edective by the operation of trip 7 before the generator is rendered eective by the operation of switch 53. The means for' disengaging the initial spinning means and for shutting on' the supply of gas .is old in the art (see patents to Leavitt No. 1,145,025, July 6, 1915, and Dieter No. 1,148,154, July 27, 1915) and need not be described here. While the use of oxygen is preferable, it will be understood that hydrogen may be utilized in a similar mannerA for initial spinning up.

In the form of invention shown in Fig. 4, two reduction valves 71 and 72 for the hydrogen tank 2 are placed side by side, while the starting valve 73, operated by latch 74, does not have combined therewith a reduction valve as in Fig. 1. oxygen and hydrogen tanks instead of being placed one above vor parallel to the other, are placed end to end with a water-nlled partition or gas-trap between them as shown in Fig. 5. lThe oxygen tank 3 is similarly provided with reduction valves 75 and 76 and starting valve 77. Latch 74 has a direct connection with starting valve 77' and a pin-and-slot connection with starting valve 73, so that the oxygen will be fed to the combustion chamber before the hydrogen. 'I'he vcombustion chamber 78 is again projacket positively to prevent overheating of thel water in the jacket by means such as a pump 82 driven from the turbine shaft through an eccentric 83 or the like, the pump being connected tothe water tanks by pipes 84. The water is The' brought under suitable pressure between 500 pounds and 3000 pounds for example, by being connected by pipe 85 to pipe 86 connecting reducing valves 71 and 72. .The Oxy-hydrogen flame is projected into the combustion chamber by burner 87 which is fed by pipes 88 and 89 leading from valves 73 and 77, respectively. The water may be projected into the lcombustion chamber in opposite direction to the ame by means of a spray nozzle 90 connected to the water tank through pipe 91. The mixture may be ignited by the sparking device 3l of Fig. 1 or the continuously-burning cartridge 35 of Fig. 4.

Preferably also, I provide means for preventing the production of too great heat or too great pressure, or both, within the combustion chamber. This may be accomplished by thermostatic and pressure regulation of the ow of combustible mixture through the burner, or the amount of water injected, or both. For this purpose I have .shown la pressure regulator which may be located in a side wall of chamber 78 as governing the admission of gases, and a thermostat as governing the supply of water. Said pressure regulator 100 is arranged to close contacts 92,- 93 100 push to the left lever` 95 which is pifvoted to rod 96 connected to the armature oi the solenoid, thereby simultaneously partially closing gas valves 72 and 76 through valve stems 97 and 98. Preferably also, said lever 95 is connected by a link 99 to a corresponding lever 101 connected with valve stems 102, 103 of valves 71 and 75, so that all of said valves are partially closed when the pressure within the chamber reaches the limit of pressure. As soon as the pressure is reduced, however, the regulator opens the contacts and the valves are restored to their normal position by spring 104.

The maximum pressure to be maintained within the chamber 78 can be regulated by adjusting the pressure regulator 100. Although various forms oi adjusting mechanisms may be employed either to vary the tension of spring 105 or the distance between contacts 92 and 93, I have illustrated one means of the latter type. For this' purpose, contact 93 is mounted movable relative to contact 92 as by means of gear 106 engaging rack 107 on a shaft suitably supported in a bracket and which 1255 carries said contact 93 at its other end. The shaft 106 carrying gear 108 extends through the torpedo casing to permit rotation from outside the casing. By increasing the gap between contacts 92 and 93 the maximum pressure within chamber 78 is increased, while by decreasing the distance between the contacts, the maximum pressure is decreased. The maximum pressure w;th.in the combustion chamber may thus be regulated at will.

Since the pressure upon the water in the reservoirs (in Fig. a), or reservoir .(in Fig. 1) depends upon the pressure existing between valves 71 and 72 (in Fig. 4) or valves 8 and 6 (in-Fig; A1), it is apparent that by varying the degree of opening M@ of the valves, the pressure transmitted to the reservoirs through pipe85, for example, is dependent upon the pressure existing between the y reducing valves. By varying thesupply of gas corresponding to the maximum pressure in thev combustion chamber, the amount of water supplied is correspondingly varied.

For controlling the temperature within the combustion chamber, I control the admission of water preferably thermostatlcally. For this purpose I have shown the thermostat 108 which may be located in the steam delivery pipe 81. Said thermostat is arranged to close contacts 109 and 110 when the temperature in said passage becomes too high. Said contacts excite solenoid 111 connected to a lever 112 secured tothe stem of valvel113 to increase the supply of water injected into chamber 78. When the temperature falls suiiiciently, the supply of water is decreased by the thermostatically-controlled means.

It will be understood that the pressure-regulat` ing and temperature-controlling devices have v been illustrated in connection with chamber 78 s .dizing name, thus avoiding damage to the combustion chamber and other parts of the apparatus through oxidation at the high temperatures prevailing in the system. The amount of hydrogen in excess should be regulated for keeping it within desirable limits to prevent waste of the gas and discharge of a sufllcient quantity of it from the exhaust of the turbine to make a visible wake. I have therefore provided in the exhaust of the turbine, a hydrogen detector whereby the percentage of excess hydrogen may be kept within any desired limits, even approaching zero.

The hydrogen detector which I employ may be such. as described in U. S. Patent of vPreston R. Bassett, No. 1,467,084 dated September 4, 1923, the resistance of a certain coil being greatly reduced whenever hydrogen is present. For this purpose I provide preferably in the exhaust of the turbine two receptacles 115 and 116, one of which (here shown as 116) is sealed, while the other is open to the exhaust gases. Through each of said receptacles passes a conductor 117, 118, having a well-deilnedtemperature coeflicent and -forming two arms of a Wheatstone bridge. The other two arms of said bridge are known resistances 119 and 120, the source of E. M. F. is the battery 33, and the voltmeter is shown at V, The wire 118 being sealed will not come in contact with the exhaust gases, but the wire 117 being exposed to said gases will, when a change in the amount of hydrogen passing over it occurs, vary its conductivity (because the greater the quantity of hydrogen, the more heatl is abstracted from conductor 117) Any disturbance of the balance of the Wheatstone bridge will be apparent on the voltmeter. In order that the conductors may be 'maintained at the same temperature, receptacle 116 is constructed with thin walls of a highly conductive material, such as copper. The conductors 117, 118 are preferably formed of an aluminum-coated steel or iron wire known as calorized wire. The degree o! excess of hydrogen may be regulated through the degree of unbalancing of the bridge. p

When a predetermined excess of hydrogen is present, there will be a predetermined reading of the voltmeter causing contacts and 126 to engage and'close a circuit through a solenoid 'traveled an exactly straight course, prongs 165 relatively the amount of hydrogen and also increasing relatively the amount of oxygen. By this means the proper balance between the two gases may be maintained, so that complete combustion is secured with the desired excess of hydrogen. Not only the driving of the torpedo is accomplished by my invention without a visible wake being produced, but-also the maintenance of said torpedo at a predetermined depth below the surface and on a predetermined course I accomplish by means which yield no visible wake. For controlling the course of the torpedo I may employ the gyro 50. The steering rudders are iixed upon a shaft 136 to which is attached a lever 137, the ends of said lever being connected by cables 138 and 139 to the arms of a bell-crank 140 piv-I oted at 141.v The bell-crank is provided with a third arm 142 pivoted to a bell-crank 143 having arms 144 and 145. Links 146 and 147 are pivotally connected respectively at one end to arms 144 and 145 ofvbell-crank 143 andhaving their v other ends pivoted to the torpedo casing. Arm 144 and link 146 thus form one knuckle or toggle and arm 145 andlink 147 a second knuckle or toggle, and when said second toggle is straightened out (as shown in Fig. 2)' bell-crank 140 is rotated in one direction to rotate rudders 135 to "Je limit of their throw in one direction, while when said rst toggle is straightened out, the bellcrank 140 is rotated in the opposite direction to rotate rudders 135 to the limit of their throw in the opposite direction. 'I'he toggles are oppositely acting. For straightening the toggles the tail shaft may be provided with a gear meshing with a gear 151 on a shaft 152 carrying an eccentric 153 adapted to oscmate nk 154 and lever 155 connected to said link. faid lever is pivoted at 156 and carries at its lo'wer end (in Fig. 2) a block 157, to which it is pivotally connected by a pin-and-slot connection 158, 159 said pin operating against the action of a spring 160 in saidslot. The block 157 carries a prong 161 adapted to engage selectively the' ends of links 162, 163 connected to the pivots of toggles 145, 147 and 144. 146, respectively, to straighten said toggles and thus operate the rudder to one side or the other. y

Means are provided for operating the rudder in a direction to restore the torpedo to thevpre- 125 determined course. For this purpose, block 157 is provided with a forwardly-extending fork having prongs 165, 166 to either side of a projection 167 carried -by the gyroscope. If the torpedo and 166 would not engage the projection 167, 130 block 157 wouldbe centrally positioned, and both toggles would be operated to the same extent, so that the rudder would not be displaced. The torpedo travels, however, a sinuous course, so that except when the torpedo passes through central position, the gyroscope is always turned with respect to the torpedo, and projection 167 will engage prong or 166 to rotate block 157, so that prong 161 engages link 162 or 163. Pins 170 limit the rotation of the block. The gearingis such that block 157 will be rotated by the gyroscope in a direction to cause prong 161 to engage that link (162 or 163) which will operate the rudder in a direction to return the torpedo to its course. As the torpedo returns to its course and swings beyond it, block 157 will be rotated by the gyroscope to cause prong 161 to engage the other link and actuate the rudder in the opposite direction.

It will be apparent that I have provided a 1 purely mechanical, non-gas emitting device for operating the steering rudders so that no wake is produced thereby.

Similarly, I provide a'non-gas-emitting depth control device. For this purpose, I mount upon shaft 152 (which is driven from the tail shaft) an' eccentric 171 which is in engagement with, a frame 172 slidably mounted in a partition or bracket 173 and has pivotally mounted thereon a pair of spaced arms 174 and 175 slidably supported in a link 176 suspended from* the torpedo shell by a bracket 177. Between said arms is positioned a shaft 180 having xed thereon a pair of oppositely-toothed ratchets 181 and 182 with which engage pawls 183 and 184 on arms 174 and 175, respectively. The supporting link 176 is adapted to maintain the arms 174 and 175 spread apart so that not more than one of said arms can have its pawl in engagement with the respective ratchet at any given time, and in centralized position neither pawl engages its ratchet. The link 176 is connected to one arm 185 of a bellcrank 186, the otherarm of which is connected in a suitable manner, as by a cable 187 to a hydrostatic control which can be set for a predetermined depth. When the torpedo moves to some diierent depth, the bell-crank 186 isrotated in one direction to operate link 176- to cause one of the pawls to engage its respective ratchet and rotate shaft 180 in the same direction. A spiral 188 is formed on shaft 180 and in the'groove formed by said spiral operates the end of an arm 189 of a bell-crank or walking-beam pivoted at 190, the ends of the other arms of said bell-crank being connected by cables 191, 192 to the depth rudders 193. Obviously, rotation of the spiral by one pawl and ratchet in one direction will rotate the depth rudders in a given direction and rotation of the spiral in the other direction by the other pawl and ratchet will rotate the depth rudders in the othervdirection. The gearing is such ythat when the predetermined depth is exceeded, the rudders are operated in a direction to raise the torpedo and when the predetermined depth has not been reached, the rudders are operated to lower the torpedo.

Bell-crank 186 is pivoted to one arm of bell-` crank 194 pivoted on the iixed frame at 195, the other arm of bell-crank 194 being connected by a link 196 to one arm of walking-beam 189, so that as said beam is operated to vary the position of the depth rudders, a follow-up system is actuated to disengage vthe pawl from the ratchet. The depth rudders remain in the set position (since after the pawl and ratchet have been disengaged, there is no further actuation of said rudders'if until the predetermined depth is reached. The torpedo continues in the same direction beyond the predetermined depth, whereupon the other pawl and ratchet become eiective to operate the depth rudders in the opposite direction. When the predetermined depth is reached, neither pawl is in engagement with its ratchet and there is no actuation of the depth rudders.

It is thus apparent that the depth control operating mechanism, like the course-control operating mechanism, is actuated without the production or emission of a gas which would form a visible wake or track.

In accordance with the provisions of the patent statutes, I have herein described the principle of operation of my invention, together with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understoodyftliat the apparatus shown is only illustrative and that the invention can be carried out byf'other means. Also, while it is designed touuse the various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a torpedo having a course control rudder and gyroscope, in combination, means for driving said torpedo, means for operating said rudder, means for maintaining the spin of said gyro, and a steam generating apparatus employing nothing but oxygen., hydrogen and water, all of said means being operated from said steam generating means without emitting a persistent gas.

2. In a torpedo having a course control rudder, means for driving said torpedo, a purely mechanical connection between said means and said rudder for operating the latter in either direcytion, said connection comprising apair of oppositely-actingioggles, and a directive gyro for selectively engaging said toggles to control the direction of operation of the rudder.

4il. In a torpedo having a course-control rudder, means for driving said torpedo, a purely mechanical connection between said means and Said rudder for operating the latter in either direction, said connection comprising a pair of oppositely-acting toggles, means connected to said toggles whereby they are operated, and a directive gyro selectively engageable with said last-named means for controlling the direction of operation of the rudder.

d. In a torpedo having a depthcontrol rudder, means for driving said torpedo, a purely mechanical connection between said means and said rudder, saidv connection comprising driving means for operating said rudder upwardly or downwardly, depth responsive means for controlling said driving means, and a follow-up means from said rudder to said driving means to render the latter ineffective.

5. In a torpedo having a depth control rudder, means for driving said torpedo, a purely mechanical connection between said means and said said rudder upwardly or downwardly, said driv-` ing means being normally ineffective, depth-responsive means selectively connected to said pair oi driving means to render one or the other of said driving means effective foroperating the rudderin the desired direction, and a followl up means from' said rudder to said driving means for rendering the latter ineffective.

7. In a torpedo having a depth control rudder, means for driving said torpedo, a purely mechanical connection between said means and said rudder, said connection comprising a pair of oppositely-disposed ratchets, a pair of pawl members engageable with said ratchets for operating said rudder upwardly or downwardly, said pawlmembers being no 'y ineffective, depth-re.- sponsve 'means connected to said ratchet mem# bers to render onev or the other thereof eiective for operating the rudder in the desired direc- Ation, and a. follow-up means fromsaid rudder to ing said torpedoand means for operating sai gyroscope, both o! said means including a. source said huid beinl 00inof uid under pressure. pletely soluble in water.

EDWARD G. SPERRY, Ezecutor of the Estate of Elmer A. Sperry.

'los

no l

Ill- 

